The present invention relates to an automatic shut-off valve, and also to a pressure-regulator including such valve. The invention is particularly useful in water irrigation systems, and is therefore described below with respect to this application, but it will be appreciated that the invention could advantageously be used in other applications as well.
One type of water irrigation system with respect to which the invention is particularly useful is one including a plurality of water sprinklers each of which is equipped with an automatic shut-off valve such that all the water sprinklers will automatically be turned on when the inlet pressure reaches a predetermined value and will be automatically turned off when the inlet pressure drops to a predetermined low value. Such water irrigation systems, particularly those involving a long line of water sprinklers, frequently include a pressure regulator to assure that all the water sprinklers will operate at the same pressure irrespective of the pressure drop along the length of the line.
An object of the present invention is to provide an automatic shut-off valve of the foregoing type made of a few simple parts which can be produced and assembled in volume and at low cost. Another object of the invention is to provide such a valve in which the closing pressure can be changed in a simple and inexpensive manner. A further object of the invention is to provide an automatic shut-off valve which can, by the addition of a simple part, be converted for use also as a pressure regulator to regulate the outlet pressure.